Cu-I-mediated degradation of polysaccharides leads to fragments with narrow polydispersities

Biomass derived oligo- and polysaccharides are important compounds for various applications, including biomedicine and material science. Their use, however, is often limited by inherent structural inhomogeneity of the starting materials. Here, a method for depolymerization of naturally occurring polysaccharides, including dextran, starch, xylan and galactoglucomannan, into well-defined fragments of narrow polydispersities is described, based on the use of in situ generated Cu-I species under the commonly employed CuAAC reaction conditions. The main strength of the reported method is its high versatility, both in terms of substrate scope and operational simplicity.